The Raman spectra of Cr₃O₈ and Cr₂O₅

The Raman spectra of polycrystalline Cr 3 O 8 and Cr 2 O 5 powders were measured. The powders were prepared by thermal decomposition of CrO 3 under flowing oxygen. Their composition was verified with x‐ray diffraction. Raman spectra were excited with both 514.5 and 647.1 nm radiation. The spectral intensities were corrected for wavelength‐dependent instrumental response. Tentative peak descriptions were made by comparison of the Cr 3 O 8 and Cr 2 O 5 spectra with reported spectra of crystalline chromium oxides.